#include<stdio.h>
void change(int a, int b)
{
	int t = a;
	a = b;
	b = t;
}
 
int main()
{
	int a = 10;
	int b = 20;
	printf("交换前a=%d，b=%d\n", a, b);
 
	change(a,b);
 
	printf("交换后a=%d，b=%d\n", a,b);
 
	return 0;
}